Slug-casting mold



R. R. MEAD Swe CASTING mom) Filed April 9, 1925 2 Sheets-Sheet 1 Jan. 12 1926. 1,569,386

I INV'ENIOR Jan. 12 1926. 4 1,569,386

R. R. MEAD .SLUG CASTING MOLD Filed April 9, 1925 2 Sheets-Sheet 2 7 'IVNVENTOR Patented Jan. 12, 1925.

UNITED STATES PATENT OFFICE.

GUERNEY H.. COLE, OF FOREST HILLS, PENNSYLVANIA, ASSIGNOR TO WESTINGHOUSE TYPE COMPANY, A CORPORATION OF NEW YORK.

SLUG-CASTING MOLD.

Applicationpfiled. April' 9, 1925. Serial No. 21,760.

T 0 all whom it may conce n:

'Be it known that I, RICHARD R. MEAD, a citizen of the United States, residing at Brooklyn, in the county of Kings and State of New York, have invented certain new and useful Improvements in Slug-Casting Molds, of which the following is a specification.

This invention relates to typographical casting machines, such as linotype machines of the general organizationrepresented in U. S. Letters Patent to O. hIergenthalenllO. 436,532, wherein a melting pot is arranged to deliver molten metal into a slotted mold 'andup-against a composed line of matrices to produce a type bar or slug bearing on its edge type characters corresponding to the intaglio characters of the matrices. As these molds are usually constructed, the side walls of the mold slot or-cavity are formed by a bottom or body portion and an upperor cap portion, while the end Walls are formed by two end portions or liners held in place between the body and cap portions. Ordinarily, the moldsare made to produce slugs not exceeding 30 ems in length, but for certam classes of work, such as advertis ng or bookrwork, the molds are made to produce slugs running as high as 42 ems in length.

In the manufacture of the mold parts, which are made of steel, it is essential to harden them, or at least those portions which form the mold'cavity, in order to avoid the adherence of molten metal to the mold surfaces as well as to resist wear upon such surfaces during the ejection of the cast slugs. This hardening process necessarily "sets up internal stresses in the metal and gives rise to warping or distortion of the casting surfaces when the mold is in use Thus, when the molten metal is injected into the mold, the mold surfaces become quite hot, and the stresses, being relieved, tend to readjust themselves upon the subsequent cooling of the mold surfaces, causing the warping or distortion just referred to. As a result, and particularly in the case of the larger molds, imperfect slugs are produced and, moreover,

' damage to the mold and to the trimming and ejecting mechanism oftentimes occurs. Such warping or distortion is confined almost entirely to the body and cap portions of the mold (the liners being comparatively small) and is accentuated by reason of the peculiar formation of these parts, which are made of irregular shape or contour and of non-uniform cross-section.-

The present invention is intended to obviate the foregoing difficulties and conten1 plates an improved form of mold, whose side Walls, although hardened as before, will be effectively prevented from warping or twisting out of proper shape. To this end,

it is proposed; to construct the mold body, as Well as the mold cap, in two sections, stead of 1n one integral piece, as heretofore,

the inner or base sections (which constitute I the sidewalls of the mold slot) being hardened according to any of the Well-known methods, and the outer sections (which constitute reinforcing members for the side walls) being left in unhardened condition. Inmaking up the mold body and the mold cap in such composite fashion, the inner base portions may be of substantially uniform thickness and cross-section, while the outer reinforcing portions may be of any desired shape or cross-section, it being possible, as intended, to design the parts so that the completed mold will be substantially identical in formto the standard mold now in use. In hardening the base portions, certain in ternal stresses will be set up therein as or course, but these inherent stresses, due to the reduced thickness and the more nearly uniform cross-section of the base portions, will be materially less than before, and hence not so apt to cause warping or distortion of the mold surfaces during the slug casting periods. On the other hand, the outer reinforcing portions, which are not hardened, will be free from internal stresses and consequently not subject to warping or distor tion during the slug casting periods, so that whenthese reinforcing portions are applied to the base portions they will serve as rigid supports therefor and maintain them in proper shape. In other words, even though the hardened base portions are inherently subject to warping in some degree, notwithstanding their reduced and-uniform crosssection, such warping tendency will be reill as such limitations are specified in the claims.

Referring to the drawings:

Fig. l is a perspective view, partially disl. lcd. of the proposed mold;

2 is a front elevation thereof, as-

3 is a top plan View of Fig. 2; and Fi l is a vertical transverse section, taken on the line l-l of Fig. 2.

Although equally applicable to the ordinary unrecessed mold or to mmds of other sizes, the invention has been herein illustrated as applied to a em mold of the re cessed or head-letter variety. Generally, the mold proper comprises the body A, the cap ll, and the intermediate liners C, D, these parts being held together in assembled relation by posts E rising from the body A and engaging in notches formed in the opposite ends of the cap B. The cap B is formed as usual, with the longitudinal groove B in its front face and on its under face with a series of transverse depending blocks or core sections B projecting into the mold slot or cavity. So far as described, the parts may be the same as those embodied in any commercial mold of the recessed type and in themselves constitute no part of this invention.

According to the present invention, the mold body A is made up of an inner hardened steel base portion A constituting the lower side wall of the mold cavity, and an outer unhardened steel reinforcing portion AF, the two sections having a machined lit and. held together by clamping screws A. i iilzeivise, the mold cap B is made up of an inner hardened steel base portion B consti sting the upper side wall of the mold cavity, and an outer unhardened steel reinforcing portion B the two sections also having a machined lit and held together by clan'iping screws B In this latter instance, dowel pins B are or may be employed to assist in locating the parts in proper relation to each other. It may be noted that the rcinforcing portions A and B are of the customarv rm and outline, so that when the r s are assembled. the entire mold substantially identical in form he with the standard molds now in us, in Fig. '2, the composite mold sl'iovrn mounted in the customary aperture formed in the mold Wheel or disc F and is held in place therein by means of the customary clamping screns F On the other hand, the inner base portions A and B,

which constitute the opposite side Walls of the mold cavity, are of substantially uniform thickness and cross-section throughout.

As the mold is thus constructed, when the base portions of the body and cap are heattreated for hardening purposes, the stresses set up are substantially uniform and have less tendency to cause distortion or Warping of the mold surfaces during the intermittent slug casting operations. 'IoWever, Whatever tendency there may be to distortion or warping in use, such tendency is resisted and largely overcome by the attached unhardened reinforcing portions, Which have no internal stresses and which, therefore, are not subject to distortion or Warping in use. ll'hile the hardening of the inner base portions may be carried out in some other Way, it is proposed in the manufacture of the im proved mold to make said portions of nonshrinkable tool steel and harden them by quenching in an oil bath, an added advan tage which comes from the composite structure of the mold cap and mold body.

It will be understood that in carrying out the present invention, it is not absolutely essential that the reinforcing portions A and B be secured directly to the base portions A and B although such arrangement is preferred, as such reinforcing portions may be supported independently of the base portions, as for instance by the mold disc or Wheel F, and then clamped tightly down upon the base portions. In such embodiment of the invention, the reinforcing portions should be made adjustable in order to receive the base portions and to apply the necessary pressure thereto When the parts are brought together, as Well as to permit the separation of the base portions in changing the liners in varying the dimensions of the mold cavity. The broad invention in this regard resides in a composite mold having hardened steel side Walls and reinforcing members applied to the side alls serving to' resist Warping or distortion thereof.

Having thus described my invention, its construction and mode of operation, What I claim and desire to secure by Letters Patent of the United States, is as follows: 1

1. In or for a slug-casting machine, a composite mold having hardened steel side Walls, and reinforcing members applied to the side walls and serving to resist Warping or distortion thereof.

2. In or for i a slug-casting machine, a composite mold having hardened steel Walls and unhardened steel reinforcing members applied to said alls.

'3. A mold body comprising a hardened 1 steel base portion and an unh'ardened steel reinforcing member secured thereto.

4. A mold cap comprising a hardened steel base portion and an unhardened steel reinforcing member secured thereto.

5. In or for a slug-casting machine, a composite mold having hardened steel side Walls of substantially uniform cross-section, and reinforcing members applied to the side Walls to resist warping or distortion thereof.

6. In the method of manufacturing slugcasting molds, forming the mold cap and mold body each in tWo steel sections, one an inner base portion and the other an outer reinforcing portion, and hardening the base portions Without hardening the reinforcing portions.

7. In the method ofmanufacturing slugcasting molds, forming the side Walls of the mold cavity of hardened steel, and applymg to said side Walls reinforcing portions of unhardened steel.

8. In the method of manufacturing slugcasting molds, providing inner steel base portions to constitute the side Walls of the mold cavity and separate outer steel reinforcing portions for application to said base portions, hardening the base portions, and leaving the reinforcing portionsunhardened, for the purpose described.

In testimony whereof, I have afiixed my signature hereto.

RICHARD R. MEAD.

Certificate of Correction.

It is hereby certified that in Letters Patent No. 1,569,386, granted January 12, 1926, upon the application of Richard R. Mead, of Brooklyn, New York, for an improvement in Slug-Casting Molds, an error appears in the printed specification requiring correction as follows: Page 1, in the heading, names of patentee and assignee strike out lines 3 and 4: and insert instead Richard R. Mead, of Brooklyn, New, York, asstgnon t0 Mengenthale'r Linotype Company, a Corporation of New Y 0170. and that the said Letters Patent should-he read with this correction therein that the same ma conform to the record of the case in; the Patent Office.

Signed and sealied this 9th day of February, A. D. 1926.

[SEAL] WVM. A. KINNAN,

Acting Commissioner of Patents. 

